Process of producing fast dyeings



Patented Nov. 19, 1 946 PROCESS OF PRODUCING FAST DYEINGS ON ARTIFICIAL FIBERS WITH DYESTUFFS OF THE GALLOCYANINE CLASS Georges de Niederhausern, Basel, Switzerland, as-

signor to Durand & Huguenin A. G., Basel,

Switzerland No Drawing. Application July 6, 1942, Serial No. 449,956. In Germany July 1.6, 1941 7 Claims.

In the periodical American Dyestuii Reporter, vol. 28, part 20, 1939, pages 582-590 there is found a report on the dyeing of nylon fibers, i. e. of fibers of superpolyamides, which are entirely synthetic fibers of highly molecular artificial substances of the kind of polyamide and obtained by polycondensation of primary or secondary diamines with a dicarboxylic acid or with an amide forming derivative of a dibasic carboxylic acid. That publication contains tables giving a survey of the aifinity of different series of dyestufis to the fibers mentioned before, as well as tables illustrating the fastness properties of the dyeings.

It has been found that the gallocyanine range not mentioned in the said tables, especially the series being derived from an aniline, methylated on nitrogen such as dimethylaniline, 'monomethyl-o-toluidine and others, further from gallic acid or from a derivative thereof are excellently adapted for the dyeing of such fibers. The dyestuff is applied to the fiber in a leuconic form, from an alkaline vat and the dyeing is developed thereon in a bath containing a salt of chromic acid and an acid. The dyeings thereby obtained possess a .good fastness to soaping and to rubbing and in particular an excellent fastnes to light.

Besides the gallocyanine dyestuiis mentioned above, other dyestuffs of the said class such as gallocyanines, generally derived from an alkylated (e. g. ethylatedlor arylated aniline, further the condensation products of gallocyanines with amines and with phenols are suitable for the present new dyeing process. The present process is especially suitable for gallocyanine dyestuffs bearing no sulpho groups.

Gallocyanine-dyestufis which are soluble in water may also be applied to nylon fibers in a non-leueonic form, from a neutral bath or a bath containing small quantities of acetic acid and may be developed with bichromate and acid. However, the dyeings thus obtained are considerably weaker than those produced from an alkaline vat by the present process.

The following examples serve to illustrate, without limiting, the present process:

Example 1 4 g. of the gallocyanine-dyestuff obtained from nitroso-dimethylaniline and gallic acid are pasted with 30cc. of a 1:10 diluted caustic sodalye 38 Be. and poured on with boiling water until the complete solution of the dyestuff is obtained. The dyestuff. thus dissolved is added to the dyebath. .Then follows an addition of 2 g. of Brilliant Avirol L 142 come. (see periodical The Dyer, Calico Printer, Bleacher and Finisher 1932, page 678), after which the quantity of the bath is brought to 2 litres by addition of water. Then 4 g. of hydrosulphite conc. are added to the bath whilst stirring thoroughly and 100 g. of nylon yarn, previously wetted, are entered. After a short treatment at about 40 C. the temperature is raised within /2 hour to 90 C. and this temperature is maintained for hour. In the course of dyeing the dye-bath must keep its (yellow) colour of reduction, which can be attained by adding from time to time a little amount of hydrosulphite cone. After dyeing the goods are rinsed thoroughly, whereby it is advisable to add still some hydrosulphite to the first rinsing bath. After rinsing, development is carried out during /2 hour at 40-45 C. in an acid oxidation bath containing 0.5 g. of potassium bichromate and 0.2 cc. of formic acid of per cent strength per litre. The dyeing operation is finished by rinsing again thoroughly and eventually by soaping.

In this way a deep navy blue shade With excellent fastness properties is obtained.

Example 2 If in the foregoing example instead of the mentioned dyestuff the gallocyanine-dyestufi from nitrosodimethylaniline and methylic ester of gallic acid is used, a deep navy blue shade, possessing very good fastness properties is also obtained. This dyeing may be shaded with a yellow dyestuff which is stable to hydrosulphite and to alkalies, e. g. with yellow wood extract (fustic), whereby valuable black shades are obtained.

Instead of the above mentioned dyestufis from nitrosodimethylaniline and gallamide, nitrosomonomethyl-o-toluidine and gallamide may be applied in the same way and with the same results for the dyeing of the new fiber.

Thus are obtained dark navy blue to violet shades with good fastness properties.

, Example 3 The following dye-bath is prepared:

I Parts Gallocyanine dyestufi" from nitrosodimethylaniline and gallanilide 2 Caustic soda lye of 4% NaOH 3!) Boiling water 1,250 A solution of 1:10 of the wetting agent named Brilliant-Avirol L 142 cone. (see Example 1) 20 Cold Water 694 I-Iydrosulphit cone 4 100 parts of the fiber which has to be dyed are entered in the dye-bath. Within hour the temperature of the bath is raised to 90 C. and this temperature maintained for hour. If necessary, small quantities of hydrosulphite are added during the course of dyeing. Subsequently the goods are thoroughly rinsed and developed during hour at 45 C. in a fresh bath prepared as follows:

' Parts Water 1,860 Solution of potassium bichromate (1:100) 100 Formic acid 80% (1:100) 40 After development the goods are rinsed and soaped at 90 C, for hour and a dark navy blue shade of very good fastness properties is obtained. In place of the above mentioned dyestuff its leuco compoundprepared according to the method already known, for instance by reduction with the aid of zinc dust and hydrochloric acidmay also be applied.

100 parts of nylon yarn, previously wetted, are entered into this bath and the hanks are well worked. The temperature is raised within hour to 90 C. and maintained for another 1; hour. If necessary, small quantities of hydrosulphite must be added. After the above indicated time the yarn is taken out of the bath, squeezed andthoroughly rinsed. Development is carried.

out for hour at 45 C. in a fresh bath set as follows:

Potassium bichromate grams 0.5 Formic acid 80% cubic centimeters" 0.2

perlitre. The yarn is then thoroughly rinsed and soaped.

"In this way' a bright reddish blue shade with good fastness properties is obtained.

'The gallocyanine-dyestuif from nitrosodiethylaniline can be replaced by one of the following dyestuffs, whereby apart from the difierences of shade, the final result is quite similar to that of this example: 7

NitrosomonoethyLo-toluidine and gallamide Nitrosoethylbenzylaniline and gallamide Nitrosodiphenylamine and gallamide Example The anilino compound of the gallocyanine dyestufi from nitrosodiethylaniline and gallamide is converted into the respective leuco compound according to the process disclosed in the U. S. Patent No. 929,350.

The product of condensation resulting from 2 parts of this leuco compound are dissolved in 100 parts of nylon yarn, previously wetted, are entered into this bath and the hanks are well worked. The temperature of this bath is raised to 90 C. within hour and this temperature maintained for hour. After rinsing, development takes place during hour at 45 C. in a fresh bath containing:

. Parts Water 1,860 A solution of potassium bichromate (1:100) 100 Formic acid (1 100) 40 The yarn is then rinsed and soaped for hour at C. Thus fast greenish blue shades are obtained.

In the same way dyeings with other anilino compounds of gallocyanine-dyestuffs, for instance with the anilide 0f the dyestuif from nitrosodi methylaniline and gallamide, with the anilide of the dyestuff from nitrosodimethylaniline and gallanilide with the anilide of the dyestuff from nitrosodiethyl-m-toluidine and gallamide, generally with the condensation products of amines with gallocyanines may be obtained.

- Example 6' l The following dye-bath is prepared:

Parts the action of resorcinol on the gallocyanine-dyestuff from nitrosodiethylaniline and gallamide (see U. S. Patent No.

In this bath parts of the fiber are dyed and developed as described in Example 5.

A fast dyeing of a dark blue shade is obtained. What I claim is:

1. A process for producing dyeings on nylon fiber with gallocyanine-dyestuffs which comprises applying on to the fiber a dyestuff of. the said group in leuconic form, from an alkaline vat, and developing the jdyeing thereon by an aftertreatment in a bath containing a salt of chromic acid andan acid, and finally soaping.

2. A process for producing dyeings on nylon fiber with gallocyanine dyestuffs which comprises applying on to the fiber a gallocyanine-dyestuff derived from a methylated aniline in leuconic form, from an alkaline vat, and developing the dyeing thereon by an after-treatment in a bath containing a salt of chromic acid and an acid, and finally soaping. I

3. A process for producing dyeings on nylon fiber with gallocyanine-dyestuffs which comprises applying on to the fiber a gallocyanine-dyestufi' obtainable from nitrosodimethylaniline and gallanilide in leuconic form, from an alkaline vat, and developing the dyeing thereon by an aftertreatment in a bath containing a salt of chromic acid and an acid, and finally soaping.

4. A process for producing dyeings on nylon fiber with gallocyanine-dyestufis which comprises applying on to the fiber a condensation product of an amine with a gallocyanine-dyestuff in leuconic form, from an alkaline vat, and developing the dyeing thereon by an after-treatment in a bath containing a salt of chromic acid and an acid, and finally soaping.

5. A process for producing dyeings on nylon fiber with gallocyanine-dyestufis which comprises applying on to the fiber the anilino compound from the gallocyanine 'dyestuff obtainable from nitrosodiethylaniline and gallamide in leuconic form, from an alkaline vat and developing the dyeing thereon by an after-treatment in a bath containing a salt of chromic acid and an acid, and finally soaping.

6. A process for producing dyeings onnylon fiber with gallocyanine-dyestuffs which comprises applying on to the fiber a condensation product of a phenol with a gallocyanine-dyestufi in leuconic form, from an alkaline vat, and developing the dyeing thereon by an after-treatment in a bath containing a salt of chromic acid and an acid, and finally soaping.

'7. A process for producing dyeings on nylon fiber with gallocyanine dyestuffs which comprises applying on to the fiber the condensation prodnot from resorcinal with the gallooyanine dyestuif obtainable from nitrosodiethylaniline and gallamide in leuconic form, from an alkaline vat, and developing the dyeing thereon by an aftertreatment in a bath containing a salt of chromic acid and an acid, and finally soaping.

GEORGES DE NIEDERHAUSERN. 

